"Pennsylvania has a challenge to continue to be good stewards of Penn's Woods, but we also have an obligation to the truth, and that we put terms like 'Rust Belt' and 'Brain Drain' onto the ash heap of history," said Cawley.

Concerning the truth, Cawley can't resist tall tales. What that says to me is that he is incapable of making a strong case for shale gas. Cawley must lie in order to convince PA residents that drilling is in their best interests. An obligation to the truth doesn't apply to Cawley. It only applies the anti-fracking crowd.

State or municipal intervention needs to be smart as well as properly resourced. Prof Glaeser is scathing about the efforts to rehabilitate Detroit, for example, where money was thrown at construction but achieved negligible results.

By contrast, Pittsburgh has transformed itself from a city decimated by the decline of the steel industry on which it was built into a contemporary metropolis of tech clusters and vibrant neighbourhoods. Its success seems to result from a lucky combination of careful, consistent investment and seed money for start-ups from the Pittsburgh Technology Council (established perceptively early in 1983), while it is an ethnically mixed city of lively and distinctive neighbourhoods defined by good restaurants and cafés and, critically, cheap property prices.